code: def test_overlay_iter(self):
      views = [self.view1, self.view2, self.view3]
      overlay = NdOverlay(list(enumerate(views)))
      for el, v in zip(overlay, views):
          self.assertEqual(el, v)
  
file_path: holoviews/holoviews/tests/core/test_layers.py
imports: import unittest
  import numpy
  from holoviews import Element, NdOverlay
label_desc: Use image node_id 2 for calling the OverlayTest obj's underlying member method code with example usage: obj.test_overlay_iter() without return types